CMD
*
STATUS
TX BIT
BIT
WORD
TX DIS
CMD
DATA
*
STATUS
his mode command is not normally used in dual redundant
systems.
The device will respond with status and shut down the transmitter
on the bus designated by the two least significant bits of the data
word.
The bus addresses of the device are channel 0 - 00, channel
1 - 01. If the command is received on the same bus as the
designated shut down bus then the device will respond with status
and no shut down will occur.
Once a transmitter has been shut down it can only be reactivated by
an 'Override Shutdown Command' or 'Reset Remote Terminal'.
If the command was a broadcast the status transmission will be
suppressed and the broadcast bit in the status register set.
TX EN
CMD
DATA
*
STATUS
14
SCDCT2578 REV B 3/11/98
Error Conditions
Action taken by device
1. Invalid command.
No response.
Command ignored.
2. Command followed by
another word.
No status response.
Set message error.
Sequence terminated.
3. T/R bit of command set
to zero.
No status response.
Set message error.
Sequence terminated
4. Broadcast address.
No status response.
Set message error.
Set broadcast.
Sequence terminated.
5. T/R bit of command set
to zero and broadcast
address
No status response.
Set message error.
Set broadcast.
Sequence terminated.
Error Conditions
Action taken by device
TRANSMIT BIT WORD (13)
On receipt of a valid Command to transmit the BIT Word the
device will respond with Status followed by the BIT word, after
which the BIT register is cleared.
Bits 2 to 15 are always zero. Bit 1 is set if the subsystem sends too
many NSSTRB’s.
Error Conditions
Action taken by device
1. Invalid command.
No response.
Command ignored.
2. Command followed by
another word.
No status response.
Set message error.
Sequence terminated.
3. T/R bit of command set
to zero.
No status response.
Set message error.
Sequence terminated
4. Broadcast address.
No status response.
Set message error.
Set broadcast.
Sequence terminated.
5. T/R bit of command set
to zero and broadcast
address
No status response.
Set message error.
Set broadcast.
Sequence terminated.
SELECTED TRANSMITTER SHUTDOWN (14)
1. Invalid command.
No response.
Command ignored.
2. Command not followed
contiguously by data
word
No status response.
Set message error.
Sequence terminated.
3. Command followed by
too many words.
No status response.
Set message error.
Sequence terminated
4. T/R bit of command set
to one.
No status response.
Set message error.
Sequence terminated.
5. T/R bit of command set
to one and broadcast
address
No status response.
Set message error.
Set broadcast.
Sequence terminated.
OVERRIDE SEL TRANSMITTER SHUTDOWN (15)
This mode command is not normally used in dual redundant
systems.
he device will respond with status and reactivate a shutdown
transmitter on the bus designated by the two least significant bits
of the data word.
he bus addresses of the device are channel 0 - 00 channel
1 - 01. If the command is received on the same bus as the
designated override shutdown bus then the device will respond
with status and no reactivation will occur.
the command was a broadcast the status transmission will be
suppressed and the broadcast bit in the status register set.